" Common language runtime and associated files required to run applications developed to target the .NET Framework 3.0. "- From Microsoft

The Microsoft .NET Framework 3.0 is the new managed code programming model for Windows. It combines the power of the .NET Framework version 2.0 with new technologies for building applications that have visually compelling user experiences, seamless communication across technology boundaries, and the ability to support a wide range of business processes. These new technologies are Windows Presentation Foundation, Windows Communication Foundation, Windows Workflow Foundation, and Windows CardSpace.

The .NET Framework 3.0 is included as part of the Windows Vista operating system; you can install it or uninstall it using Windows Features Control Panel.

This redistributable package is for Windows XP and Windows Server 2003.

For customers that already have the .NET Framework 2.0 installed, this .NET Framework 3.0 redistributable package installs only the new Windows Vista components. This ensures that any .NET Framework 2.0-based applications work seamlessly when the .NET Framework 3.0 is installed, with no application migration or updates of any kind required.